A probabilistic approach for the assessment of the influence of the dielectric constant of pore fluids on the liquid limit of smectite and kaolinite

Liquid limit (L,L) is defined as a limiting water content separating the viscous liquid state and plastic state of soil consistency. LL of clays, being a basic physico-chemical property, plays a role in environmental geotechnical engineering practice. Since it is well-known that kaolinite and smectite behave quite differently from each other from the geotechnical point of view, ninety-one data regarding smectite (Na and Ca) and kaolinite mixed with organic pore fluids having different dielectric constant (epsilon) values have been carefully analyzed. Data confirm that for a decreasing epsilon value of the pore fluid a decrease in LL is observed for the smectitic clays, with different magnitude depending on the main ion, whereas for kaolinitic clays this decreasing epsilon causes an increase in attractive forces causing flocculation and increase in LL values. A probabilistic approach has been performed to assess the robustness of the regression functions. For smectitic and kaolinitic clays the mathematical dependency of LL with epsilon is validated by the probabilistic analysis.